My original hair color is a dirty blonde. I have been highliting my hair with blonde highlites for quite some time. I want to dye my hair a all over lighter blonde. Will dying my hair blonde somehow make the highlites already in my hair turn a weird color?

It depends on the color of the highlights-
And the shade of the blonde-
What SHOULD happen is the original highlights
Will be lighter than the new blonde color- giving you highlights
In your blonde hair-
HOWEVER
Some blonde products will deposit pigment in your highlights
Leaving you with blond hair and orange or purple highlights
Call a hairdresser (a professional one) and ask some advice
Or... just use a hair color stripper to remove the highlights first

Thanks spyderglass for your response! I just wanted to let everyone know that I did dye my hair over the highlights and it turned out perfectly! No weird color at all!

Good!